It was a tiny component of the overall rebuild and would not delay the scheduled building completion time of this winter, nor would it add costs to the stadium rebuild. The affected contractor would pay, he said. The fact the problem was picked up and was being fixed showed how well the rigorous quality control checks during the construction process were working, Mr Dennis said.

Steel, concrete and other materials used on the stadium were being tested all the time and if they weren't up to scratch they were replaced.

"We [the stadium trust] aren't going to accept anything less than 100 per cent . . . The system we have in place ensures if the steel isn't of great quality it will be rectified."

"Because it's a very strict process it's inevitable that issues arise. That's quite normal in any large building project."

The quality control procedures in place for the building were expensive but necessary, he said.

Everything done on the stadium was peer-reviewed and a fulltime clerk of works was on site to inspect all of the work.

The stadium is being rebuilt because the original stadium collapsed under a heavy dumping of snow in September 2010.

The new stadium is bigger and stronger than its predecessor and its rebuild has been blighted by cost blowouts and time delays.

Mr Dennis said the aim was to have the new stadium comply with 100 per cent of the new earthquake standards.

"Obviously with the history of the building we aren't taking any risks with anything."